Subterranean slurry mining apparatus

ABSTRACT

A bit attached to a tool string is used for drilling a hole from the ground surface into or through a subterranean deposit of granular ore. Within the tool string is a passage through which fluid flows to the bit while drilling. Valve means positioned within the passage are controllable from the ground surface for diverting the flow of fluid from the bit to an eductor located above the bit for mining operation. A nozzle in the tool string, located above the eductor, is controllable from the ground surface to discharge a jet stream of fluid radially outward from the tool string for breaking up the ore matrix. Then the eductor pumps a slurry mixture of fluid and granular ore through the tool string to the ground surface.

Wenneborg et al.

[ July 24, 1973 SUBTERRANEAN SLURRY MINING APPARATUS Inventors: WilliamZ. Wenneborg, Pocatello,

Idaho; Bobby R. Payne, Charleston, W. Va.; Philip R. Bunnelle, SantaClara, Calif.

Assignee: FMC Corporation, New York, N.Y.

Filed: June 1, 1971 Appl. No.: 148,501

US. Cl 175/87, 175/213, 175/215, 175/67, 299/17 Int. Cl E21b 7/18 Fieldof Search 299/17; 175/422, 175/213, 231,217,215, 87, 324, 65

References Cited v UNITED STATES PATENTS 3,439,953 4/1969 Pfefferle299/17 Primary Examiner-Marvin A. Champion Assistant Examiner-Richard E.Favreau Attorney-Nicholas DeBenedictis, J. W. Edwards, Eugene G. Seemsand Pauline Newman [57] ABSTRACT A bit attached to a tool string is usedfor drilling a hole from the ground surface into or through asubterranean deposit of granular ore. Within the tool string is apassage through which fluid flows to the bit while drilling. Valve meanspositioned within the passage are contro1- lable from the ground surfacefor diverting the flow of fluid from the bit to an eductor located abovethe bit for mining operation. A nozzle in the tool string, located abovethe eductor, is controllable from the ground surface to discharge a jetstream of fluid radially outward from the tool string for breaking upthe ore matrix. Then the eductor pumps a slurry mixture of fluid andgranular ore through the tool string to the ground surface.

PIITENTED 3. 747. 696

sIIazI 01 or 10 SLURRY INVENTORS WILLIAM LWENNEBORG BOBBY R. PAYNE BYPHILIP R. BUNNELLE ATTORNEYS PATENIED JUL 24mm 3, 7, 595 sum 02 0F 10T'IE 1 PAIENTED m 24.913 3.141. 696

SHEET U HJF 10 T'IE EI PATENIED JUL24|975 3. 74']. B96

SHEET 05 HF 10 PATENTEU JULZMW 3. 747'. 696

SHEET 07 HF 10 'PATENTED 3.747. 696

SHEET D80! 10 SLURRY 4 11%.

111% WATER EL PAIENTED 3. 747. 696

SHEET 09m 10 F'IEL1'7 l SUBTERRANEAN SLURRY MINING APPARATUS BACKGROUNDOF THE INVENTION 1. Field of the Invention This invention relates tomining underground deposits of granular ore, such as phosphates, bydeep-well hydraulic apparatus and more particularly to a combinationwell-drilling and mining tool for extracting granular ore fromsubterranean beds.

2. Description of the Prior Art Known methods for deep-well mining ofgranular ore, such as phosphates, require pre-drilling a well and liningthe side walls with mud or a casing. Then, a mining tool is insertedthrough the well casing for disintegrating ore therebelow by jettingwater into the matrix. A slurry mix is formed and pumped upward throughthe mining tool to the ground surface. Such methods are expensivebecause of costs of lining the hole, assembling and disassembling thedrill pipe string, and assembling and disassembling the miningtool.

US. Pat. No. 3,311,414 discloses a well drilled by a mining tool itselfwithout predrilling. Such use of the mining tool is suitable only whereno layer of limestone or cap rock covers the phosphate matrix. Normally,there is such a layer and the hole must be predrilled and mudded beforeinsertion of the mining tool.

US. Pat. No. 3,155,177 shows apparatus for underreaming a well that canalso be used to bore-deeper in the well. Electric operated valvesconvert the apparatus from drilling operation to under-reamingoperation.

U. S. Pat. No. 1,851,565 shows a mining apparatus that is inserted intoa pre-drilled hole. A mining agent is projected from a nozzle tofluidize the substance mined and the accumulated mixture is lifted by aninjector upward through the mining apparatus to the ground surface. Noprovision is made for drilling with the mining apparatus.

In order to drill from the ground surface through any stratum to reach adeposit of granular ore, it is desirable to use a rotary typedrillingrig. Upon reaching the granular ore deposit, which can be hundreds offeet below the ground surface, it is desirable to jet a stream of fluidinto the ore matrix to form a slurry mixture of ore and water. Oneproblem encountered in developing a combination drilling and mining toolis the establishment of controls at the ground surface by whichunderground tool operation can be converted from drilling to mining.

SUMMARY OF THE INVENTION The presentinvention provides a combinationtool for drilling to subterranean deposits of granular ore and miningthe deposits at a maximum speed and with a minimum amount of toolhandling. Since the tool is driven by rotary drilling equipment, it canrapidly penetrate through any stratum to reach a granular ore deposit.It is unnecessary to linethe well or pull the tool after drillingbecause the tool string functions both as a drilling string and a miningconduit. To convert from drilling to mining operation, the tool iscontrolled'from the ground surface by increasing the quantity of fluidflow into the tool. Also, an inner casing is turned'to index adistributor nozzle for directing a jet stream of fluid through a desiredport in the tool outer casing to break up the granular ore matrixopposite therefrom. Should the sides of the well subside about thetoolafter drilling, it is unnecessary to rotate the tool outer casing in oneembodiment of the invention because the mining jet can be indexedindependently of the outer casing. The mining apparatus includes a bitattached to a tool string having an eductor therein located above thebit and a plurality of flow passages therethrough. Rotary drillingequipment drives the tool string and bit to a desired depth and adistributor nozzle within the tool string discharges a jet stream offluid outward therefrom to break up a granular ore matrix thereabout.The tool string includes an outer casing and an inner casing which turnstherein for indexing the distributor nozzle from a closed positionbetween ports during drilling to open positions in alignment with portsin the outer casing for mining. The eductor has a nozzle, plugged duringdrilling operation, which is opened by increasing fluid flow down thetool causing pressure to build up below the nozzle. A valve seals a flowpassage to the drill bit when the eductor nozzle opens, therebydivertingfluid flow to the nozzle for mining operation.

BRIEF DESCRIPTION OF THE DRAWING FIG. 1 is a broken sectional view inelevation of apparatus embodying the present invention for drilling awell.

FIG. 2 is a broken sectional view in elevation of the apparatus shown inFIG. 1 used for mining.

FIG. 3 isan enlarged central vertical sectional view of the swivel subassembly shown in FIG. 1.

FIG. 4 is an enlarged central vertical sectional view of the tool headassembly shown in FIG. 2.

FIG. 5 is a section taken on the line 55 of FIG. 4.

FIG. 6 is a broken longitudinal section of a typical tool section. l

FIG. 7 is a view looking in the direction of arrows 7-7 in FIG. 6.

FIG. 8 is a view looking in thedirection of arrows 88 in FIG. 6.

FIG. 9 is an enlarged central vertical section of the distributor shownin FIGS. 1 and 2.

FIG. 10 is a section taken on line 10-10 of FIG. 9.

FIG. 11 is a perspective view of the inner distributor with portionsbroken away to show underlying structure.

FIG. 12 is an enlarged central vertical section of the eductor nozzleand tool bit valve shown in FIGS. 1 and 2.

FIG. 13 is a perspective view of the eductor nozzle housing.

FIG. 14 is a section taken on line l4-14 of FIG. 9.

FIG. 15 is a section taken on line 15l5 of FIG. 14.

FIG. 16 is a diagrammatic view of a modified form of the invention shownin FIGS. ll5..

FIG. 17 is an enlarged vertical section through the modified tool headassemblyshown in FIG. 16.

FIG. 18 is an enlarged vertical section through the modified miningnozzle shown in FIG. 16..

FIG.19 is an enlarged vertical section through the modified eductornozzle plug and tool bit valve shown in FIG. 16. i j

FIG.- 20 is a section taken on line .20-20 of FIG. 19.

DESCRIPTION OF THE PREFERRED EMBODIMENTS With reference to FIG. 1, themining apparatus includes a drill bit 20 attached to a tool string 21that is driven by a portablerotary-type drilling rig 22. The drill bitcan be any conventional type for a rotary drill but preferably wouldhave pivotable cutter arms 20a that collapse within the body of the bitwhen the tool string is lifted. A suitable bit is manufactured byServco, PO. Box 20212, Long Beach, California, and known as the ServcoModel B Drilling-Type Hole Opener. The drilling rig has a mast 23supported on a pair of skids 24 and 25. While skids have been shown, thedrill mast could be supported on a barge or other movable mount forover-water operation or mounted on movable units such as wheeled orcrawler type vehicles for land operation.

A platform 26 has e'nds slidably engageable with tracks 27 and 28 thatextend vertically on mast 23. Mounted to the platform is a swivel 29coupled by a hanger 30 to a cable 31 which raises or lowers the platformon the mast. A rotative portion of the swivel extends through an'opening in the platform and a large sprocket 32 is keyed thereto beneaththe platform. The sprocket is driven through a chain 33 by a motor 34mounted on the platform. Since the platform and swivel for rotating thetool string can be elevated on the mast, it is possible to begindrilling a hole with the bit at ground surface without using a startingtool.

Tool string 21 is connected to the rotative portion of swivel 29 by aswivel sub-assembly 35 and drilling fluid is supplied by a hose 36 to agooseneck 37 then through the swivel and swivel sub-assembly to the toolstring. The swivel sub-assembly, shown in FIG. 3, has a stub end 40adapted for coupling with the rotative portion of the swivel and a bellend 41 that couples with the tool string. Projecting outward from thebell end is a circumferential flange 42 having a guide skirt 43 boltedthereto that depends in parallel spaced relationship with the bell end.A.passage 44 extends through'the stub end to the bell end interior wherea fitting 45 is located having a conical plug 46 and ports 47 to directfluid flow from passage 44 into an annular passage 48 between the bellend and fitting. The lower end of the fitting fits telescopically intoan inner tube socket of a dual pipe stand which will later be describedand a packing 45a is provided thereabout. Below the conical plug is apassage 45b which enables a small quantity of drilling fluid to flowdown and clean the interior of the inner tube during drilling.

Looking now at FIG. 2, a tool head 49 is shown mounted on tool string 21for mining operation. The tool head has a T-section 50 with a miningfluid or water intake conduit 51 and a bracket 52 is mounted on theT-section for supporting a reducer drive motor 53. A swivel joint 54connects the T-section with a coupling flange 55 having a large sprocket56 mounted thereon. The reducer drive motor drives a small sprocket 57and sprocket chain 58, trained about the large and small sprockets,turns the large sprocket and coupling flange. A swivel joint 59 mountedabove the large sprocket is joined to a slurry discharge conduitdensitymeasuring line 64 coupled at the top with a passage 65 extending inwardthrough the coupling flange and at the bottom with a fitting 66extending from pipe coupling 63. A pipe nipple 67 connects the fittingwith a stab joint 68 that inserts into a socket end of line 68a (FIG. 6)extending downward between inner and outer tube assemblies of the toolstring. Swivel joint 54 has an upper rotative portion 70 bolted to thecoupling flange and coupled by ball bearings 71 to a lower stationaryportion 72 bolted to T-section 50. A union fitting 73 is attached toconduit 51 of the T-section and a threaded pipe coupling 74 joins thelower end of the T-section with an outer tube assembly of the toolstring.

Tool string 21 includes a series of tool sections 75, as shown in FIGS.6, 7 and 8, that extend from swivel subassembly 35 (FIG. 1) or tool head49 (FIG. 2) through a layer of overburden OB to a subterranean depositof granular ore G.O. Each tool section has an outer tube 76 and an innertube 77. A coupling 78, welded to the upper end of the outer tube,provides an internally threaded female connection 78a, while coupling79, welded to the lower end thereof, provides a threaded maleconnection. Similarly, the inner tube has a female coupling 80 at theupper end and a male coupling 81 at the lower end, however, a key 82projecting radially inward in the female coupling interlocks in anopening 83 (FIG. 6) in the male coupling reinforced by strap 83a so thatadjacent inner tubes rotate together.

An external support flange 78b on coupling 78 is provided for supportingthe tool sections when not attached to adjacent sections. A support ring84, held in concentric spaced relationship by arms 85 and 87 outside offemale coupling 80,v seats on a thrust bearing 84a within coupling 78and lugs 86, projecting outward from male coupling 81, contact coupling79 to maintain the lower end of the inner tube 77 in alignment withinthe outer tube 76 prior to engagement with an adjacent tool section.Line 68a, for measuring slurry density, fits through a support 87located between the support ring and female coupling and through an ear88 projecting outward from male coupling 81.

The open annular cross-sectional area between the outer tube 76 andinner tube 77 is approximately the same as the open circularcross-sectional area within the inner tube. By approximately balancingthese areas, the velocity of fluid flowing downward in the annularpassage between the outer tube and inner tube is substantially the sameas the velocity of fluid flowing upward within the inner tube. The headlosses due to friction of fluid flowing in the tubes is minimized underthis condition.

Inner tube 77 is the conduit through which a slurry mixture of granularore is conveyed to the ground surface. By using the inner tube for theslurry passage, more clearance is provided for large modules of orewithin the inner tube than would be available in the annular passagebetween the outer tube 78 and inner tube. Furthermore, the slurrymixture contacts only the inner tube, which can be replaced in the eventof excessive wear.

Each tool section 75 is arranged for rapid coupling with an adjacenttool section by progressive engagement of inner tube couplings 80 and81, key 82 and opening 83, lines 68a which are connected by stab joints,and outer tube'couplings 78 and 79. O-ring seals are fitted about innertube male coupling 81, line 68a at the stab joint, and outer tube malecoupling 79 to provide fluid tight connection. Threads within outer tubefemale connection 78a'and on the male connection of coupling 79 aretapered for fast engagement and disengagement.

As shown in FIGS. 1 and 2, tool string 21 includes a distributor 90, aneductor 91 and a bit valve 92 that are located between tool sections 75and bit 20. The distributor has an outer body, as shown in FIG. 9,formed by an upper section 93 joined to lower section 94. An internallythreaded socket 95 is provided at the top of upper section 93 to joinwith male coupling 79 of a tool section 75 and an internally threadedsocket 96 is provided at the bottom of lower section 94 to join with anouter casing about the eductor. An upper ball race 97 and a lower ballrace 98 extend circumferentially about the interior of lower section 94,which has eight radial ports 99 (FIG. providing communicationtherethrough. The lower section interior surface adjacent the ports islined with hardened wear resistant material 94a.

Distributor 90 has an inner body formed by a tube 103 with a femalecoupling 104 at the top and a male coupling 105 at the bottom. Withinthe female coupling is a key 106, similar to key 82, for locking withinan opening 83 of a male coupling 81. A nozzle 107 having sets ofstraightening vanes 108 and 109 fitted therein extends transverselythrough the tube 103 which bulges thereabout perpendicular to the nozzleas shown in FIG. 10, to maintain a certain minimum cross-sectionalclearance in the tube. A cylindrical shell 110, spaced from tube 103 bya top ring 111 and a bottom ring 112, rotatably fits within the interiorof lower section 94 and has a lining 110a of hardened wear resistantmaterial opposite material 94a. The rings 1 11 and 112 have ball races113 and 114 positioned for alignment with ball races 97 and 98,respectively. Ball bearings 115 are fed through loading holes and fittedwithin the ball races enabling the cylindrical shell to turn freelywithin the lower section of the outer distributor body while held inplace axially therein. Spaced circumferentially around top ring 111 arevertical ports 116 and around bottom ring 112 are vertical ports 117which allow fluid to flow downwardly to eductor 91 and bit 20. A seal119a is positioned above the top ring while a seal 11% is positionedbelow the bottom ring to prevent fluid reaching the ball races.Positioned between tube 103 and shell 110 behind nozzle 107 is adeflector 118 for directing fluid into the nozzle.

A line 120, which couples with line 68a of tool section 75, is attachedto the outside of female coupling 104 and communicates with the interiorof tube 103 for determining fluid pressure at that location to calculateslurry density. Also attached to the outside of the female coupling isan ear 121, shown in FIG. 14 having internally threaded openings thereinto receive bolts 122 and 123 which hold in place a connecting plate 124.A rectangular slot 125 at the edge of the connect ing plate adjacentupper section 93 is aligned over a recess 126 at the base of internallythreaded socket 95. The recess is enclosed on the interior side by aplate 127 welded to the socket base and a shear key 128 fits within theslot and recess to lock tube 103 from rotation within the outerdistributor body during drilling operation. In the locked position,nozzle 107 is positioned between ports 99 to prevent fluid dischargefrom the nozzle during drilling and to prevent foreign matter fromplugging the nozzle. A multiplicity of recesses 126 are provided aroundthe socket base enabling the nozzle to be locked between any twoadjacent ports.

An outer casing 132, shown in FIG. 2, has a top portion that connectswithin internally threaded socket 96 (FIG. 9) of distributor 90, whilethe bottom portion is connected to an inlet housing 134 of eductor 91.The eductor includes a nozzle 145 within the inlet housing, a mixingchamber section 133 having a tapered entrance 133a connected to theinlet housing above the nozzle, and a diffuser tube 130 that extendsfrom the mixing chamber section to a rotatable joint 131 joining malecoupling 105.

Eductor inlet housing 134, shown in FIGS. 12 and 13, has a top ring 135and a bottom ring 136 spaced between a pair of conduits 138 and 139having vertical passages therein. These passages provide communicationfrom the annular passage between outer casing 132 and mixing chambersection 133 to a chamber 137 below the bottom ring. Radial openings 140,located between each conduit on opposite sides of the outer casing,provide communication from outside the outer casing to an axial passage141 that extends vertically above nozzle 145. These radial openingsprovide a large slurry intake adjacent the eductor nozzle to draw inamaximum quantity of ore for suction developed. The base of the conicalshaped nozzle seats within an axial opening in the bottom ring and isheld in place by an overlapping retainer ring 146 bolted to the bottomring.

Chamber 137 is enclosed by a casing 142 welded to bottom ring 136 andexternally threaded at the lower end for attachment within an internallythreaded socket 143 at the top of a bit coupling 144. An axial passage147 extends from the chamber through the bit coupling to a threadedsocket 148 where bit 20 is attached. A valve seat 149 tits in theentrance to the axial passage for bit valve 92 to seatthereon and avalve cage 150 covering the bit valve within the chamber is bolted tothe bit coupling. The bit valve has guide vanes 152 that extend downwardinto the axial passage and a flange 153 that seals the passage entrancewhen seated on the valve seat. A small passage 154 is provided in thebit valve enabling some fluid to reach the bit during mining operationfor maintaining the material thereabout in a fluidized state until thebit is raised.

Bit valve 92 is attached to a guide tube 156 that slidably flts throughvalve cage and has a sleeve bearing 157 within the upper end thereof. Astem 158 slidably fits telescopically through the sleeve bearing intothe guide tube interior where an enlarged head 159 formed on the sternprevents withdrawal of the stem from the guide tube. The stem endopposite from the enlarged head fits through eductor nozzle 145 where aplug 160 is fltted thereacross and held in place by a shear pin 161. Thestem and guide tube hold the plug in position blocking the eductornozzle and a seal under the plug prevents leakage of drilling fluidwhile the tool bit valve is retained in an elevated position at the topof the valve cage. The plug also prevents foreign matter which mightenter the eductor inlet housing 134 during drilling operations fromobstructing the eductor nozzle.

In operation, drilling rig 22 is moved to a desired location and toolstring 21, with bit 20 attached, is connected to swivel sub-assembly 35.Rotation of the drill string causes the bit to open a hole and toolsections 75 are added to the tool string until a desired depth isreached. During drilling operation, a drilling fluid such as water isfed through hose 36, gooseneck 37, swivel 29 and swivel sub-assembly 35to an annular passage between inner tube assembly 77 and outer tubeassembly 76. The fluid flows downward through the tool string past bitvalve 92 to the cutting heads of the bit and then upward between theouter surface of the tool string and sidewalls of the hole to the groundsurface as indicated by the arrows in FIG. 1.

Upon reaching the desired depth, swivel subassembly 35 is disconnectedfrom tool string 21 and tool head 49 is attached thereto. Water pumpedinto conduit 51 flows downwardly through the tool string between innertube assembly 77 and outer tube assembly 76 to bit valve 92. As the flowis increased, pressure builds up within chamber 137 to a predeterminedamount at which shear pin 161 breaks, opening eductor nozzle 145 andclosing bit valve 92.

The downward flow in tool string 21 is then directed upward througheductor nozzle 145 and inlet housing 134 to mixing chamber section 131.The jet stream through the inlet housing creates a suction that drawsgranular ore inward through radial openings 140 therein. A slurrymixture of granular ore and water flows upward, as indicated by thearrows in FIG. 2, through diffuser tube 130, distributor 90, inner tubeassemblies 77 and tool head 49 to conduit 60 from which it is dischargedinto a tank, not shown.

The slurry density can be calculated by directing a purging flow ofwater down lines 120, 68a and 64 to determine the pressure of the slurrymixture at a point above distributor nozzle 107. Then knowing thevertical distance from that point to tool head 49 and the internal crosssectional area of inner tube assembly 77, the density can be calculated.

Motor 53 can then be actuated to rotate sprocket 57 turning chain 58,sprocket 56 and inner pipe 62. Shear key 128 is broken by rotationalforce and nozzle 107 is aligned to discharge through one of the ports99. A portion of the water flowing downward in tool string 21 is thendiverted at deflector 118 into nozzle 107 to be discharged in a jetstream into a deposit of granular ore 6.0. When a sufficient amount ofgranular ore has been mined from one section of the matrix, the nozzlecan be indexed to the next port 99 and the procedure repeated until thenozzle moves through one or more complete circles. Then tool head 49 isremoved and swivel sub-assembly 35 is connected for pulling the toolstring. When a lifting pull is applied to the tool string, the pivotablecutter arms of the drill bit close enabling the bit to be withdrawn eventhough the side walls of the well have closed in about the tool string.Drilling rig 22 is moved to the next location and the procedurerepeated.

Sometimes it is desirable to control the jet flow from nozzle 107 bymeans other than input into conduit 51. Such control can be achieved bymotor 53 rotating inner pipe 62 through a drive to align the nozzle witha port 99. When the nozzle is aligned to register with the port, the jetflow discharge is at a maximum but when the nozzle is aligned betweenports, there is no discharge. By positioning the nozzle in partialalignment with the port, the effective area of the port orifice isreduced and thus the flow discharge is limited. In this manner, the headof water in the well cavity about the tool can be controlled to keepdistributor nozzle 107 above water for more effective jet action.

Another embodiment of the invention is illustrated in FIGS. 16-20. Adrilling and mining apparatus 170, shown in FIG. 16, has been modifiedfor converting back and forth between drilling and mining operations.Such a tool can mine an upper ore strata, then drill to a lower orestrata which is subsequently mined without lifting the tool. Since thedrilling and mining apparatus is in many ways similar to the apparatusshown in FIGS. 1-15, only those modified portions will now be describedin detail and it will be understood that portions not described aresimilar to previously described portions.

Drilling and mining apparatus includes a bit 171 attached to a toolstring 172 upon which a tool head 173 is mounted. The tool head is fixedto a platform 174 by a mounting ring 175. A T-section 176 is bolted tothe mounting ring and extends upward with a horizontal intake conduit177 provided for drilling and mining fluids such as water. A slurrydischarge conduit 178 extends vertically through the T-section and bendsto a horizontal alignment at the discharge end.

A motor reducer 180 mounted to the side of T- section 176 drivesshafting joined by a flexible coupling 181 and extending through bearingblock 182 to turn a drive sprocket 183. The drive sprocket is connectedby a sprocket chain 184 to a driven sprocket 185 mounted on a rotativeportion of tool head 173 to which tool string 172 is attached.

With reference to FIG. 17, mounting ring 175 has a pair of ball races187 and 188 spaced vertically along an interior face thereof. Fittingwithin the mounting ring is a casing 189 that has ball races on theouter face to mate with ball races in the mounting ring. The casing isrotatively suspended by ball bearings inserted in place within the ballraces and centered in alignment with the axis of T-section 176. Drivensprocket 185 is fixed to the casing below the mounting ring for rotatingthe casing and a threaded male coupling 190 is provided at the lowermostend of the casing for attachment to tool string 172.

Within casing 189, an inner ring 191 is aligned axially with slurrydischarge conduit 178 and supported by lugs 192 and 193 that projectinward from the casing beneath a flange 194 on the inner pipe. A seal195 is provided between the inner pipe and slurry discharge conduit tomake the joint therebetween fluid tight. Spacer lugs 196 and 197maintain the inner pipe in axial alignment within the casing and a malecoupling 198 at the lower end of the inner pipe fits telescopicallywithin a female coupling 199 of an inner tube in tool string 172.

Hydraulic fluid is supplied to tool head 173 through a line 200 thatthreadably fits into T-section 176. A passage 201 extends within theT-section from line 200 to the joint between the T-section and casing189. An annular passage 202 formed between seals 203 and 204 iscontinuously in flow communication with passage 201. A drain passage 205is provided in the T-section to relieve excessive fluid that seepsbetween a seal 204a and seal 204.

A passage 206 extends from annular passage 202 through casing 189 andsupport lug 192 to a line 207 coupled with spacer lug 196. From line207, a passage 208 extends through spacer lug 196 and inner pipe 191 toa conduit 209 that passes down the interior of male coupling 198overlapping female coupling 199. An annular passage 210 formed betweenthe male and female couplings is connected by a port with conduit 209.Extending outward from the annular passage through the female couplingand a support lug 212 is a passage 21! to which a line 213 is connectedfor providing hydraulic fluid to the tool string 172.

Within tool string 172 is a mining nozzle 215, shown in FIGS. 16 and 18,that extends transversely through an inner tube 216 to the outer surfaceof an outer casing 217. This nozzle is fixed in position between theinner tube and outer casing and to orient the nozzle, it is necessary torotate the tool string. A longitudinal passage 218 extends through thenozzle to an orifice 219 located at the discharge end thereof. Fluidflow from the nozzle is controlled by a valve stem 220 that slidablyfits through ring guides 221a and 222b supported by straightening vanes221 and 222 within the longitu dlnal passage. A seal 223 located at oneend of the valve stem is adapted to block orifice 219 when positionedtherein to prevent loss of fluid and avoid plugging of the nozzle byforeign matter during drilling operation.

Near the end of valve stem 220 opposite from seal 223 is a vertical slot224 in which the end of lever arm 225 is slidably coupled. Thus, onlyhorizontal force is transmitted to the valve stem, though the end of thelever arm moves through an arc. The opposite end of the lever arm ispivotably connected to an ear 227 fixed to inner tube 216. One end of arod 228 is pivotably connected to an intermediate point of the leverarm, while a piston 229 fixed to the opposite rod end is slidably fittedwithin a hydraulic cylinder 230. A coil spring1231 fits around the rodbetween the piston and hydraulic cylinder end adjacent the lever arm tourge the rod in the direction opposite from the lever arm.Conversely,apassage 232 connects line 213 with the hydraulic cylinderand fluid pressure urges the piston in the opposite direction. It willbe seen that the valve stem is resiliently held in a position blockingorifice 219 until hydraulic pressure applied to the piston forces thelever arm and valve stem rearward opening the orifice.

With reference to FIGS. 16,19 and 211, an eductor 235 located withintool string 172 below mining nozzle 215, is similar to previouslydescribed eductor 91. However, hydraulic operated valve means controlfluid flow to an eductor nozzle 236 and to bit 171. A single actinghydraulic cylinder 237 is bolted to a bottom ring 238 which supports thenozzle. A double end rod 239 extends through the hydraulic cylinder anda piston 240 is mounted intermediately thereon within the hydrauliccylinderfFitted around the rod between the piston and a lower end 241 ofthe hydraulic cylinder is a coil spring 242 which urges the pistonupward. A seal 243 is provided at the upper end of the rod to blocknozzle orifice 244 when the spring forces the piston to a top end 245 ofthe hydraulic cylinder. A valve 246, mounted at the lower end of therod, seats within axial passage inlet 247 leading to the bit when thepiston is forced downward to the position shown in FIG. 19. Hydraulicpressure is transmitted to the top side of the piston through a passage248 to the top end 245 of the hydraulic cylinder which is connected toline 213/ Operation of the embodiment of the invention illustrated inFIGS. 16-20 differs from that of the previously described embodiment asfollows: During drilling, no hydraulic pressure is applied to line 200in tool head 173 so nozzle orifices 219 and 244 are blocked, while axialpassage inlet 247 is open allowing fluid to flow to bit 171. Uponreaching a desired depth for mining, hydraulic pressure is applied toline 200 and is.

transmitted through line 213 causing nozzle orifices 219 and 244 to beopened and valve 246 to be closed. Drilling fluid flows downward, asindicated by solid line arrows 2511 in FIG. 19, and upward througheductor nozzle 236. Flow through the nozzle creates a suction that drawsin slurry, as represented by dotted line arrows 251, which flows upwardthrough eductor 235. The mining operation is conventional but to rotatemining nozzle 215, the entire tool string 172 is rotated by drivensprocket in the same manner as when drilling. After mining one orestrata, it may be desirable to drill down further and mine a lowerstrata. This can be accomplished by reducing the fluid pressure appliedto line 200, allowing nozzle orifices 219 and 244 to be blocked whilevalve 246 is opened, and proceeding with drilling until the second orestrata is reached. Then fluid pressure is applied to line 200 and miningoperation is resumed.

Although the best mode contemplated for carrying out the presentinvention has been herein shown and described, it will be apparent thatmodification and variation may be made without departing from what isregarded to be the subject matter of the invention.

What we claim is: I

1. Apparatus for mining a subterranean deposit of granular orecomprising a bit, and a tool string attached to the bit for drilling ahole from the ground surface through a layer of overburden into saidgranular ore deposit; said tool string having a passage therein throughwhich fluid flows to said bit during drilling operation, an eductorlocated in the tool string above said bit, hydraulic operated valvemeans located in said passage for closing off fluid flow to said bit andallowing fluid flow to said eductor for mining operation, and a slurrypassage centrally situated within said tool string through which fluidand granular ore are conveyed from the eductor to the ground surfaceduring mining operation.

2. The apparatus described in claim 1 including means for directing somefluid downward through the slurry passage during drilling operation tokeep the passage clean.

3. The apparatus described in claim 1, wherein said bit has movablecutters extendable by applying torsional forces such that said bit opensa hole larger than the outside diameter of the tool string but retractsto less than the tool string diameter for withdrawal from the hole whenthe torsional forces are relieved.

4. The apparatus described in claim 1 including a nozzle located withinthe tool string above the eductor for directing a jet stream of fluidoutward from the tool string during mining operation to break up agranular ore matrix thereabout and means for modulating the flow offluid from said nozzle independent of the quantity of fluid supplied tosaid tool string passage.

5. The apparatus defined in claim 1 wherein said hydraulic operatedvalve means, held in place by. a deformable member, are actuated bydeformation of the member in response to a predetermined fluid pressuredeveloped by increasing fluid flow down the tool string passage towardsthe bit.

6. The apparatus defined in claim 5 wherein said eductor includes anozzle andsaid hydraulic operated valve means for diverting fluid flowfrom said bit to said eductor includes a plug fitted across said eductornozzle, a valve fitted within said fluid flow passage to said bit, andmeans interconnecting saidplug and valve to maintain the nozzle pluggedand the valve open until said predetermined pressure is reachedwhereupon said interconnecting means separate to open the nozzle andseat the valve.

7. The apparatus defined in claim 6'wherein said valve has a passagetherein through which a small amount of fluid can flow to the bit duringmining operation to maintain the material about the bit in a fluidizedstate until the bit is lifted.

8. The apparatus defined in claim 6 wherein said plug and valveinterconnecting means include a valve cage fitted across the fluid flowpassage to the bit for retaining the valve therein, a guide tubeconnected to the valve and slidably fitted through the valve cage, astem linked to the guide tube, and a shear pin fastening the plug to thestem whereby said valve is retained in an open position within the valvecage and said plug is held over the nozzle.

9. Subterranean mining apparatus as described in claim 1, including anozzle located within said tool string above'the eductor for directing ajet stream of fluid outward from the tool string to break up a granularore matrix thereabout, and means for sensing pressure of the mixture offluid and granular ore in the slurry passage near the nozzle.

10. The apparatus described in claim 9 wherein said nozzle is rotatablymounted with rotating means such that it can 'be moved in a horizontal"plane without rotating said. tool string and bit. ,1

The apparatus described in claim 1 including means for actuating saidhydraulic operated valve means, independent of the fluid pressure in thetool string passage below the eductor.

p12. The apparatus described in claim 11 wherein said eductor, has anozzle andqsaid hydraulic operated valve means includes a hydrauliccylinderwith a double end rod, a valve attached to one end of the rodand adapted to seat within the fluid flow passage to the bit, and a plugattached to the outer end of the rod and adapted to block avpas's age inthe eductor nozzle, said hydraulic cylinder being operable to move thedouble end rod alternately opening the valve and plugging the nozzle orseating the valve and withdrawing the nozzle plug.

13. The apparatus described in claim 1 including a nozzle located withinthe tool string above the eductor for directing a jet stream of fluidoutward from the tool string during mining operation to break up agranular ore matrix thereabout and means for blocking the nozzle duringdrilling operation to prevent discharging fluid therefrom and pluggingof the nozzle with extraneous matter.

14. The apparatus described in claim 13 wherein said nozzle has alongitudinal passage extending transversely of the tool string to anorifice at the discharge end of the nozzle, a valve stem slidablyfitted'for longitudinal movement within the longitudinal passage andadapted to block the orifice when, positioned therein, and control meansfor slidably moving said valve stem between positions opening andblocking the orifice.

15. The apparatus described in claim 14 wherein said control meansinclude hydraulic controls that regulate the hydraulic operated valverneanssimultaneously for drilling or mining operations.

'16. In subterranean mining apparatus, a tool string having an innertube assembly and an outer tube assembly, said outer tube assemblyhaving a plurality of radial ports spaced circumferentially thereaboutat one level,

said inner tube having a nozzle therein at the level of said radialports for directing a jet stream of fluid therethrough, and means forrotating said inner tube assembly relative to said outertube assemblyand thereby indexing said nozzle withsaid radial ports.

17. In subterranean mining apparatus as described in claim 16, means'forlocking saidinner tube assembly with said outer tube assembly when thenozzle is'positioned between two radial ports, saidlocking means beingshearable by rotative force-applied by said rotating means to index saidnozzle withsaid radial ports.

18. The apparatus described in claim l'tiwherein said nozzle ispositioned in partial alignment with a port to reduce the fluid flowtherethrough.

19. The apparatus described in claim 16 including ballbearingspositioned between said inner and outer tube assemblies tohold thenozzle at the level of the radial ports and to reduce rotationalfriction between the inner and outer tube assemblies.

UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent: No.3,747,696 Dated July 24, 1973 Inventor(s) William Z Wenneborg, et al Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 8, line 38, "ring" should read --pipe--.

Column 11, line 38, "outer" should read -other*-.

Signed and sealed this 24th day of June 1975.

SEAL) Attest:

C. E 'IARSHALL DANN RUTH C. MASON Commissioner of Patents ArrestingOfficer and Trademarks FORM PO-105O (10-69) USCOMWDC 503764,

* us. sovsnuusm PRINTING omcz nu O-8i6-33L

1. Apparatus for mining a subterranean deposit of granular orecomprising a bit, and a tool string attached to the bit for drilling ahole from the ground surface through a layer of overburden into saidgranular ore deposit; said tool string having a passage therein throughwhich fluid flows to said bit during drilling operation, an eductorlocated in the tool string above said bit, hydraulic operated valvemeans located in said passage for closing off fluid flow to said bit andallowing fluid flow to said eductor for mining operation, and a slurrypassage centrally situated within said tool string through which fluidand granular ore are conveyed from the eductor to the ground surfaceduring mining operation.
 2. The apparatus described in claim 1 includingmeans for directing some fluid downward through the slurry passageduring drilling operation to keep the passage clean.
 3. The apparatusdescribed in claim 1, wherein said bit has movable cutters extendable byapplying torsional forces such that said bit opens a hole larger thanthe outside diameter of the tool string but retracts to less than thetool string diameter for withdrawal from the hole when the torsionalforces are relieved.
 4. The apparatus described in claim 1 including anozzle located within the tool string above the eductor for directing ajet stream of fluid outward from the tool string during mining operationto break up a granular ore matrix thereabout and means for modulatingthe flow of fluid from said nozzle independent of the quantity of fluidsupplied to said tool string passage.
 5. The apparatus defined in claim1 wherein said hydraulic operated valve means, held in place by adeformable member, are actuated by deformation of the member in responseto a predetermined fluid pressure developed by increasing fluid flowdown the tool string passage towards the bit.
 6. The apparatus definedin claim 5 wherein said eductor includes a nozzle and said hydraulicoperated valve means for diverting fluid flow from said bit to saideductor includes a plug fitted across said eductor nozzle, a valvefitted within said fluid flow passage to said bit, and meansinterconnectinG said plug and valve to maintain the nozzle plugged andthe valve open until said predetermined pressure is reached whereuponsaid interconnecting means separate to open the nozzle and seat thevalve.
 7. The apparatus defined in claim 6 wherein said valve has apassage therein through which a small amount of fluid can flow to thebit during mining operation to maintain the material about the bit in afluidized state until the bit is lifted.
 8. The apparatus defined inclaim 6 wherein said plug and valve interconnecting means include avalve cage fitted across the fluid flow passage to the bit for retainingthe valve therein, a guide tube connected to the valve and slidablyfitted through the valve cage, a stem linked to the guide tube, and ashear pin fastening the plug to the stem whereby said valve is retainedin an open position within the valve cage and said plug is held over thenozzle.
 9. Subterranean mining apparatus as described in claim 1,including a nozzle located within said tool string above the eductor fordirecting a jet stream of fluid outward from the tool string to break upa granular ore matrix thereabout, and means for sensing pressure of themixture of fluid and granular ore in the slurry passage near the nozzle.10. The apparatus described in claim 9 wherein said nozzle is rotatablymounted with rotating means such that it can be moved in a horizontalplane without rotating said tool string and bit.
 11. The apparatusdescribed in claim 1 including means for actuating said hydraulicoperated valve means independent of the fluid pressure in the toolstring passage below the eductor.
 12. The apparatus described in claim11 wherein said eductor has a nozzle and said hydraulic operated valvemeans includes a hydraulic cylinder with a double end rod, a valveattached to one end of the rod and adapted to seat within the fluid flowpassage to the bit, and a plug attached to the outer end of the rod andadapted to block a passage in the eductor nozzle, said hydrauliccylinder being operable to move the double end rod alternately openingthe valve and plugging the nozzle or seating the valve and withdrawingthe nozzle plug.
 13. The apparatus described in claim 1 including anozzle located within the tool string above the eductor for directing ajet stream of fluid outward from the tool string during mining operationto break up a granular ore matrix thereabout and means for blocking thenozzle during drilling operation to prevent discharging fluid therefromand plugging of the nozzle with extraneous matter.
 14. The apparatusdescribed in claim 13 wherein said nozzle has a longitudinal passageextending transversely of the tool string to an orifice at the dischargeend of the nozzle, a valve stem slidably fitted for longitudinalmovement within the longitudinal passage and adapted to block theorifice when positioned therein, and control means for slidably movingsaid valve stem between positions opening and blocking the orifice. 15.The apparatus described in claim 14 wherein said control means includehydraulic controls that regulate the hydraulic operated valve meanssimultaneously for drilling or mining operations.
 16. In subterraneanmining apparatus, a tool string having an inner tube assembly and anouter tube assembly, said outer tube assembly having a plurality ofradial ports spaced circumferentially thereabout at one level, saidinner tube having a nozzle therein at the level of said radial ports fordirecting a jet stream of fluid therethrough, and means for rotatingsaid inner tube assembly relative to said outer tube assembly andthereby indexing said nozzle with said radial ports.
 17. In subterraneanmining apparatus as described in claim 16, means for locking said innertube assembly with said outer tube assembly when the nozzle ispositioned between two radial ports, said locking means being shearableby rotative force applied by said rotating means to index said nozzlewith said radial ports.
 18. The apparatus described in claim 16 whereinsaid nozzle is positioned in partial alignment with a port to reduce thefluid flow therethrough.
 19. The apparatus described in claim 16including ball bearings positioned between said inner and outer tubeassemblies to hold the nozzle at the level of the radial ports and toreduce rotational friction between the inner and outer tube assemblies.